Alameda: On Saturday, Oct. 31, from 1 to 5 p.m., there's a DJ and games at 2324 Alameda Ave. and trick-or-treating around the downtown district. Participating businesses have a "We Have Candy" sign in the window.

Berkeley: On Oct. 31, Berkeley Public Library's Halloween Extravaganza, with the Story Time Band and Fratello Marionettes, runs 10 a.m. to noon at The Freight, 2020 Addison St. From 3 to 5 p.m., more than 80 Fourth Street shops at 1776 Fourth St. offer trick-or-treating, plus bubble and magic shows and face painting. Both are free.

Hayward: The Hayward Area Historical Society's "Monsters and Marigolds" runs 11 a.m. to 2:30 p.m. Oct. 31 at 22380 Foothill Blvd. and covers both Halloween and Día de los Muertos. It's free.

Walnut Creek:

  • Toddler storytime, Thursday, Oct. 29, 10:15 a.m., Walnut Creek Library.
  • Joybound's pet-friendly Howl & Meow-o-ween Fest, Friday, Oct. 30, 3–8 p.m., 2890 Mitchell Drive.
  • Candy giveaway, Saturday, Oct. 31, 11 a.m.–1 p.m., Security Public Storage, 2690 N. Main St.